Evolutionist don't understand what macro-evolution/micro-evolution is.

[CrazyScientist]

The question is: Where has evolution resulted in speciation? If dogs and cats have a common ancestor, why are their DNA layouts incompatible?

The fact that you ask this shows that you are very close to understanding this but are not quite there. Dogs and cats are different species because they are sexually incompatible. If they weren't, then they would still be one species and we would still have that common ancestor around. That is the point of Gothmog's fly examples above. Two populations of the same species can evolve to be sexually isolated from one another. Once that happens, changes in one can occur without affecting the other, so they diverge phenotypically.

Lets run with your example and speculate & simplify a bit. Let's say few million years ago we have this dog/cat common ancestor running around. Lets call it a cog, but imagine it's pretty much like a primitve dog (or cat, whichever you prefer). Different populations of cogs in different areas are under slightly different selection pressures, so variation develops within the populations. Some groups may get more dog-like, others more cat-like, but they migrate, and there is interbreeding, so they all stay cogs because they are all breeding and so those dog-like or cat-like genes are diluted & bred out. Now let's say we have one population that for whatever reason becomes genetically incompatible with the other populations. See my post regarding pre&post mating isolation above. Now if it gets more cat-like, what's stopping it? It can't breed with the other cogs to get back it's doggyness. If being catlike is beneficial to it in its envrionment, then selection will cause it to continue to get more & more catlike until it is in fact, a cat.

 

[Phydeaux]

Just because there are harmful mutations doesn't mean there aren't beneficial ones, also always remember this: "mutants aren't monsters" (I forgot who coined that). A mutant may be one with different pigmentations or a modified enzyme that functions better.

Not really, a lucky mistranslation and you're there!

And yes, they have been seen!

http://www.gate.net/~rwms/EvoEvidence.html

Here's my favorite, it shows an expiriment that created multiple beneficial mutations!

The thing is that it is an experiment. Even if there where beneficial mutations in nature there wouldn't be enough, because they are so rare. Also with out fast mutations the gape theory is dead.

 

[Desmond Hawkins]

You know Phydeaux if you really would like to learn something, you should read the posts in this thread with an open mind, but if you are trying to disprove them, you are doing a terrible job and are wasting everyone's time.

 

[stormbind]

That is the point of Gothmog's fly examples above. Two populations of the same species can evolve to be sexually isolated from one another.

I have not yet verified this. Is there no other example?

Now let's say we have one population that for whatever reason becomes genetically incompatible with the other populations. See my post regarding pre&post mating isolation above.

I agree with everything you said except that rather big assumption about suddenly becoming genetically incompatible.

How/why do populations of the same ancestory become genetically incompatible?

I think most species actually have a different number of chromazones, but that's not something that can be observed as happening gradually.

How can (any-)evolution account for such a change in DNA structure?

 

[The Last Conformist]

No-one's arguing that wings arose out of the blue, overnight.

Phydeaux, are you aware of the concept of "exaptation"?

 

[The Last Conformist]

The thing is that it is an experiment. Even if there where beneficial mutations in nature there wouldn't be enough, because they are so rare. Also with out fast mutations the gape theory is dead.

Do you happen to have any actual data on mutation rates to prove it wouldn't be enough?

(I don't have any to prove it is enough, but given the fossile record, fruitfly experiments, the success of domestication of animals and plants, I feel confident that the burden of proof rests on your side.)

 

[stormbind]

The thing is that it is an experiment. Even if there where beneficial mutations in nature there wouldn't be enough, because they are so rare. Also with out fast mutations the gape theory is dead.

Sickle cell anemia is a genetic "disease" that affects the amount of oxygen your blood can carry (I think), you wouldn't want it ... except if you lived in mosquito ridden tropics. People with this genetic mutation are immune to maleria, and they therefore survive (natually) in places where other humans wouldn't. Practically eveyone in their local populations carries this gene, because if they didn't... they wouldn't live to reproduce!

This is a very strong example of a genetic mutation, and it supports microevolution.

However, it's not an example of species change. It does not support the concept of macroevolution.

 

[betazed]

Phydeaux, are you aware of the concept of "exaption"?

IIRC, Gould called it "exaptation".

 

[embitteredpoet]

This is interesting as you are using intelligent reasoning and actual facts to support your argument, what I don't understand is how you are managing to ignore the wealth of facts, supporting 'macro'evolution.
Crazy Scientist, in his 'cog' post said far more eloquently what I have been trying to say.
The populations become genetically incompatible, because over time random mutations change the genetic make-up of the two groups so much that they can no longer breed to form viable offspring. This only happens because the two groups are isolated from each other and so can't exchange genes (if they could then they would be one group of organisms, natch) and so the individual mutations pile up. It is quite easy to see how a series of small changes over time can have a big effect. Read Almost Like a Whale by Steve Jones. This explains things far more coherently than I can.

 

[The Last Conformist]

@betazed: Appears you're right. My (weak) dyslexia showing again. I've somehow managed to overlook that medial -ta- every time I've read the word until today.

I'll edit my previous post.

 

[Phydeaux]

By 'not understand it' I really just meant 'God works in mysterious ways', as in 'why was my two year old son run over by that tractor' etc.

The reson why your to year son was run over by the tractor is because some one ran him over, it's not Gods falt any more than it's my'n.

I didn't mention fossils at all, I was refering to geologic evidence. And what do fossils have to do with the continuous variation in the genetic code of extant life anyway.

How can there be evidence for evolution in the gaologic record is there (other than the fossel record)?

If evolution was true you could see how the what ever changed over time.

I gave you an example of when they created something useful. Specifically a famous example of evolution through intron shuffling. Introns are bits of DNA that just jump around our genome, presumably conserved because they promote new gene formation.

And this came from a mutation? I guess you want me to look for my self.

 

[The Last Conformist]

And this came from a mutation? I guess you want me to look for my self.

Intron shuffling is a mutation.

 

[stormbind]

I discount nothing but I refuse to accept assumptions as evidence. Some scientific theories are strong, and some are weak. History shows that many have been proven wrong!

What we have with macroevolution is a qualitative explanation of a quantitative problem, which is simple "weak". I'm aiming for something a little more robust than

2+2+X+2+2 = 9 :. X = 1

That's not good enough. I want to see that X is 1, because knowing my luck, X will instead be found to be 3 + 3 - 5 ... which makes a heck of a difference to any applied science

----

Presenting stormbind's theory of macroevolution ...

Population A is the same as Population B, except for a genetic mutation, in which Population B has (recessive-gene) webbed fingers. They are the same species.

Population B then develops (dominant-gene) whisker attachments to it's webs.

Now specimen from A and B mate but the offspring cannot develop because it has nowhere to put it's whiskers.

A new species has developed.

Go ahead and debunk my theory, using scientific reason. If I just solved something, give me a medal

 

[embitteredpoet]

Well, does the mutation affect their ability to reproduce with each other in any way shape or form? NO! If the gene for not having webbed fingers is dominant, then the AB hybrid will be heterozygous, with the webbed gene repressed as it is recessive and the dominant gene expressed. A new species doesn't arise over one mutation it takes many years of isolation to cause two groups of the same species to become so dis-similar to prevent breeding.
Naturally, the amount of time taken for two groups of the same species to diverge is dependant on the rate of mutation and reproduction. Hence fruitflies are used as experimental evidence as you can go through many generations quickly...

 

[stormbind]

Wait.

Population A - has ---% dominant gene "no webs"
Population B - has 100% recessive gene "webs"

Thus the two populations look different.

Dominant whiskers affect reproductions because the RNA/DNA strands mismatch during cell reproduction. It all rides on the dominant & recessive order & combination.

 

[stormbind]

Every account of the fruitfly experiments I have read (I have now read a few online) call it nonsense. In every case, they say there was no new species.

Currently there's no observation to support macroevolution.

 

[embitteredpoet]

You have confused me now, how does an allele for whiskers affect reproduction exactly? Please explain to me what you mean by the DNA/RNA strands mismatch during reproduction and how a different allele of a gene could cause this.
Link to these sites that debunk 'macro'evolution then.

 

[Perfection]

No. I meant the preventative mechanism in their organism's biology!

To help you out, it would be covered in exhaustive detail as part of (Human) Biology (A Level) and is related to chromazones.

There's so many on this BBS who are be anti-creation, pro-evolution, and yet they don't understand the scientific inconsistency in macroevolution which fuels the scientific debate.

Are you refering to having different chromosome numbers? That's pretty simple, during meiosis nondisjunction can create a creature with an additional or lacking one, occasionally these are verile, this way evolution can change chromosome numbers. These can breed with creatures with the regular amount to produce more, eventually they may become incompatible though as the number of differences between a population that has the aneuploidy and the ones that don't create a new species.

This is only one of many ways that can cause two populations not to interbreed.

An example of another mechanism would be two populations that within a species with slightly different blood chemistry, later on in one population a vital enzyme is modified to a state more conducive with its blood chemistry however that enzyme becomes toxic in the other animals blood. So the two population's cannot successfully interbreed and so are different species.

More coming... Much much more...

 

[The Last Conformist]

Last I heard, maize can't breed with the non-domesticated percursor species. I'm sure there are other examples among domesticated plants (which often are more radically changed that ditto animals).

 

[Perfection]

Microevolution has been observed in science. That being where a population has changed by the above method ... but ... in the cases observed, and regardless of how much the populations have diverged, specimens of the new population can always breed with specimens of the former population!

Speciation has never been observed by science (emphasis). Macroevolution (large-scale evolution) specifically targets the issue of speciation.

No, speciation has been observed where they cannot interbreed

See link for examples
http://www.talkorigins.org/faqs/speciation.html

If a single mutation was responsible for speciation, then the first to mutate would be unable to reproduce, and speciation would never occur... and I remind you, science has never observed speciation.

True, that's why speciation requires multiple steps as for never observed speciation, see above link!

What is that fundamental difference in the development of a new species (macroevolution), and a subspecies (microevolution)?

Species classification does not follow an absolutely clear cut pathway. The short answer is inability to produce fertile offspring, but there are many exceptions and modifications to this basic rule, especially within the plant kingdom. Still the fuzziness of the species definition does not discredit macroevolution. Additionally, you concwpt of macroevolution and microevolution is not correct, speciation is sort of the overlapping zone between the two, where the two levels interplay, much like where in procreation the cell lineage and organismic levels interact, in demic and specific levels interact.

The thing is that it is an experiment.

mm, experiments are how science gets done.

Even if there where beneficial mutations in nature there wouldn't be enough, because they are so rare.

They're only "rare" because they're hard to isolate, consider the difficulty in trying to prove in nature that a particular trait is a new mutation and not something allready in the genome. There is, however a lot of evidence that there are based on the chemical similarity of protien structures used for different purpose.

Also with out fast mutations the gape theory is dead.

I beleive you are refering to punctuated equilibrium. Punctuated equillibrium still gives plenty of time for species to change with the observed rates of mutation, a myth about punctuated equilibrium's periods of rapid change is that the change is rapid on human scales, it is not, we're talking about a few thousand years for a species to evolve. This is plenty of time!

More to come...